linux-kernel - Re: [PATCH 3/4 RFC] RCU: preemptible RCU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Tue, 7 Aug 2007 22:32:56 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc:	linux-kernel@...r.kernel.org, linux-rt-users@...r.kernel.org,
	mingo@...e.hu, akpm@...ux-foundation.org, dipankar@...ibm.com,
	josht@...ux.vnet.ibm.com, tytso@...ibm.com, dvhltc@...ibm.com,
	tglx@...utronix.de
Subject: Re: [PATCH 3/4 RFC] RCU: preemptible RCU

On Tue, Aug 07, 2007 at 09:18:29PM +0200, Peter Zijlstra wrote:
> On Tue, 2007-08-07 at 11:48 -0700, Paul E. McKenney wrote:
> > This patch implements a new version of RCU which allows its read-side
> > critical sections to be preempted. It uses a set of counter pairs
> > to keep track of the read-side critical sections and flips them
> > when all tasks exit read-side critical section. The details
> > of this implementation can be found in this paper -
> > 
> > http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf
> > 
> > This patch was developed as a part of the -rt kernel development and
> > meant to provide better latencies when read-side critical sections of
> > RCU don't disable preemption.  As a consequence of keeping track of RCU
> > readers, the readers have a slight overhead (optimizations in the paper).
> > This implementation co-exists with the "classic" RCU implementations
> > and can be switched to at compiler.
> > 
> > Also includes RCU tracing summarized in debugfs and RCU_SOFTIRQ for
> > the preemptible variant of RCU.
> 
> Whickedly complex but very cool stuff!
> 
> Unfortunately I have nothing to contribute other than praise at the
> complex yet elegant way you dodged the need for synchronisation.

I am glad you like it!  Heck, I may have to print this email out,
frame it, and hang it on my cube wall.  ;-)

						Thanx, Paul
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/